Species and Ecosystems (should be in Bio colder) Flashcards
Ecotone
Where 2 Ecosystems interact
Intra vs. Inter species Competition
Intra: same species competing over food.
Inter: different species competing over food.
Resource Partitioning
Members of the same species sharing a food source.
Strata
Layers
Biomes
Desert: extreme temps, no rainfall.
Grassland: in NA and Asia, grass.
Savannah: Africa, Australia, and SA, dryer than grassland.
Tropical Rainforest: highest rainfall and biodiversity.
Temperate Deciduous: northern hemisphere.
Coniferous (Taiga): largest biome, cold.
Tundra: coldest
4 major rainforest zones
Canopy
Understory
Forest Floor
Soil
Freshwater Zones
Literal: from shore to where plants stop growing
Limnetic: area of open water with sunlight
Profundal: no light
Soil layers
Litter: decaying material. The better the litter the better the layers under.
Topsoil: humus, rock, air pockets, nutrients.
Subsoil:more rock, less organic matter. Water table ends here.
Bedrock: end of soil. Impermeable.
Types of Freshwater environments
Oligotrophic: mountain lakes. New, clear, deep, low nutrients, high O2, fast fish.
Eutrophic: grassland lakes. Old, muddy, shallow, high nutrients, low O2, slow fish.
Lake stratification
Occurs in summer and winter. Due to temp change. Warm water is more dense than cold water.
Layers of Freshwater
Summer: Epilimnion: Less O2, 22-18 Celsius, warmest.
Thermocline: thin layer of cooling water. 8 Celsius.
Hypolimnion: more O2, 4 Celsius, coldest.
Winter: Ice: less than 0 Celsius. Thin.
Rest starts at 2 then goes to 4 Celsius always.
Lake turnover
Occurs in spring and fall. All water reaches 4 Celsius and water mixed, scattering nutrients everywhere.
Biotic Potential
Max number of offspring a female could have given unlimited resources. Calculated by:
Birth Potential: max babies per birth.
Cap for Survival: # of offspring that live to reproduce.
Breeding Frequency: # of reproductive events in a given time/year.
Length of Reproductive Success: age of sexual maturity and # of years organism can reproduce.
Carrying Capacity
Max number of species that can be supported by the environment. Determined by two laws
Law of Minimum
Nutrients in least supply is one that limits pop. Growth.
Law of Tolerance
All organisms have an optimal range of abiotic factors for survival (pH, temp, calories).
Law of Tolerance graph/Bell Curve
Optimal range: in middle, where species prosper.
Zone of intolerance: on either side, species don’t prosper.
Area between: stress on population.
Two factors that determine population
Density Independent: don’t depend on size (fire, climate, storm).
Density Dependent: depend on density/size (disease, water, food).
3 Domains
Eubacteria: produce asexually. Live everywhere.
Archaebacteria: no peptidoglycan. Live in extreme environments.
Eukaryota: most/all are multicellular. Have nuclei.
Dichotomous Key
Ask multiple questions to determine a organisms species.
Evidence of Evolution
- Fossil evidence
- Radiometric Dating: using radioactive isotopes to create a timeline of earth.
- Biogeography: tells us all continents were one (Pangea) and species moved between them.
- Anatomy: suggest common ancestors.
- Biochemistry: DNA evidence.
Types of features in anatomy
Homologous feature: similar structure, different function (hands across all species).
Analogous feature: same structure and function but no evolutionary origin (wings in bats, birds, flys).
Vestigial feature: rudimentary features that serve no purpose, will eventually be lost (hip bones in whales).
Phylogenetic tree
Tree diagram that shows species’ common ancestors.
Greek Theory
Believe everything was created an never has or will change.
Buffon’s Theory stuff (1700s)
Georges-Louis Leclerc de Buffon notes similarities between humans and apes. Suggested a common ancestor and that earth is over 6000 years old.
George Cuvier (1800s)
Developed Palaeontology. Said that lower strata of rock held evidence of old organisms and extinctions.
Charles Lyells
Says earth was over 20 million years old due to time took for sediment layers to form.
Jean Baptist’s Lamarck
Two theories
- Spontaneous generation: living things spawned from non-living things.
- Inheritance of Acquired Characteristics: over one lifetime organisms could evolve (Lamarck’s giraffe Theory long neck boi).
Darwin
2 theories
1. Natural Selection: individuals with more favourable variations are more likely to survive and pass them on.
2. Survival of the Fittest: Individuals of a species are in a constant struggle to survive.
Big Idea: individuals with more favourable traits contribute more to gene pool, and their trait becomes more prevelent.
Causes of Mutations (mutagens)
Chemicals
UV light
Other radiation
Types of mutations
Neutral: no immediate effect on organisms ability to be successful.
Harmful (99.9% of all mutations).
Beneficial (how species evolve).
Asexual reproduction
Create exact copy of a single parent’s DNA. Used by archaebacteria, eubacteria, protists, some plants.
Sexual reproduction
Use gametes (ova and sperm) to make a zygote. Require more energy but have more genetic variation.
Speciation
The creation of new species through evolution.
Pre-zygotic isolation
- Habitat (difference in where species live).
- Behavioural (mating rituals).
- Temperal (seasonal).
- Physical (size).
- Gametic (gametes won’t work).
Post-zygotic isolation
- Viability (more susceptible to disease, etc).
2. Fertility (unable to reproduce).
Allopathic Speciation
A population is geographically separated (continental drift) and adapt to new environment. Become new species.
Sympatric Speciation
Evolution of a species while they both live in the same area
Rates of Evolution
- Gradualism: speciation occurs over long period of time.
2. Punctuated Equilibrium: world sees large explosions of speciation that slow down over time.
Types of Evolution
- Divergent: spread out from 1 common ancestor.
2. Convergent: species with no similar ancestors evolve in similar ways.
